Host processor systems may store and retrieve data using storage devices containing a plurality of host interface units (host adapters), disk drives, and disk interface units (disk adapters). Such storage devices are provided, for example, by EMC Corporation of Hopkinton, Mass. and disclosed in U.S. Pat. No. 5,206,939 to Yanai et al., U.S. Pat. No. 5,778,394 to Galtzur et al., U.S. Pat. No. 5,845,147 to Vishlitzky et al., and U.S. Pat. No. 5,857,208 to Ofek, which are incorporated herein by reference. The host systems access the storage device through a plurality of channels provided therewith. Host systems provide data and access control information through the channels of the storage device and the storage device provides data to the host systems also through the channels. The host systems do not address the disk drives of the storage device directly, but rather, access what appears to the host systems as a plurality of logical volumes. Different sections of the logical volumes may or may not correspond to the actual disk drives.
Information Lifecycle Management (ILM) concerns the management of data throughout the data's lifecycle. The value of data may change over time and, accordingly, the needs for the storage and accessibility of the data may change during the lifecycle of the data. For example, data that is initially accessed often may, over time, become less valuable and the need to access that data become more infrequent. It may not be efficient for such data infrequently accessed to be stored on a fast and expensive storage device. On the other hand, older data may suddenly become more valuable and, where once accessed infrequently, become more frequently accessed. In this case, it may not be efficient for such data to be stored on a slower storage system when data access frequency increases. Further, during data's lifecycle there may be instances when multiple copies of data exist at a particular point of time on a storage system and unnecessarily take up additional storage space.
Accordingly, it would be desirable to provide a system that allows for the efficient automatic management of data in a storage system throughout the data's lifecycle on each section of a logical volume.